Use Promises for screen.lockOrientation().

Source/modules/screen_orientation/ScreenOrientation.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef ScreenOrientation_h
 #define ScreenOrientation_h
 
 #include "core/frame/DOMWindowProperty.h"
 #include "platform/Supplementable.h"
 #include "platform/Timer.h"
 #include "platform/heap/Handle.h"
 #include "public/platform/WebScreenOrientationLockType.h"
+#include "public/platform/WebScreenOrientationType.h"
 #include "wtf/text/AtomicString.h"
 #include "wtf/text/WTFString.h"
 
 namespace WebCore {
 
 class Document;
-class ExceptionState;
+class ExecutionContext;
 class Screen;
+class ScriptPromise;

[yhirano, 2014/05/22 03:48:43]

I think this forward declaration is meaningless because you are using
ScriptPromise as a return type.

[mlamouri (slow - plz ping), 2014/05/22 08:58:56]

The forward declaration appears to be needed. It does not compile otherwise.

 
 class ScreenOrientation FINAL : public NoBaseWillBeGarbageCollectedFinalized<ScreenOrientation>, public WillBeHeapSupplement<Screen>, DOMWindowProperty {
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(ScreenOrientation);
 public:
     static ScreenOrientation& from(Screen&);
     virtual ~ScreenOrientation();
 
     static const AtomicString& orientation(Screen&);
-    static bool lockOrientation(Screen&, const AtomicString& orientation, ExceptionState&);
+    static ScriptPromise lockOrientation(ExecutionContext*, Screen&, const AtomicString& orientation);
     static void unlockOrientation(Screen&);
 
+    // Helper being used by this class and LockOrientationCallback.
+    static const AtomicString& orientationTypeToString(blink::WebScreenOrientationType);
+
     virtual void trace(Visitor* visitor) OVERRIDE { WillBeHeapSupplement<Screen>::trace(visitor); }
 
 private:
     explicit ScreenOrientation(Screen&);
 
-    void lockOrientationAsync(blink::WebScreenOrientationLockType);
-    void orientationLockTimerFired(Timer<ScreenOrientation>*);
-
     static const char* supplementName();
     Document* document() const;
-
-    Timer<ScreenOrientation> m_orientationLockTimer;
-    blink::WebScreenOrientationLockType m_prospectiveLock;
 };
 
 } // namespace WebCore
 
 #endif // ScreenOrientation_h